CANBERRA Liberals have rebuffed Tony Abbott by dumping his frontbench member in the interests of generational change.

However, Zed Seselja's victory in the preselection battle, delivered by the Young Liberals, is unsurprising, given its timing.

What surprises many in the party is that Gary Humphries reacted relatively slowly to the emerging challenge.

His ''mistake'' was to believe repeated, unequivocal assurances from Team Zed that Seselja would choose to remain ACT opposition leader for another four years rather than make the jump into federal politics ahead of a likely Coalition victory.

However, Seselja is a rising star in the Liberal Party who delivered a strong grassroots campaign in the ACT election that came within a whisker of victory.

Abbott did not comment on the result but Seselja is of the same conservative ilk as the Opposition Leader and won't cause problems by crossing the floor. Seselja will have a problem if a Coalition government puts the ACT economy into reverse by being ''forced'' to make larger than forecast cuts to the public service.

Humphries pitched himself as Canberra's champion, able to defend the city from his position on the Coalition frontbench.

Clearly, Seselja's immediate task is to stand up for Canberra and demonstrate he can get Abbott's attention.

And, since it's politics, the party will loyally unite behind the newly minted would-be senator in the interests of defeating the enemy without.

Despite the allegations of dirty tricks, the larger meeting of Liberal Party members next month can't hide from the reality that Humphries has been ambushed and dumped, and is now on the way out.

But a ticklish problem for the Liberals could be raising money for the election campaign - the Liberals' biggest funds raiser, Bob Winnel, a Humphries backer, was denied a vote in the preselection ballot.